Browse through the health section of some popular magazines and it’s easy to think that vitamin D is the next miracle cure. It seems like every health condition benefits from vitamin D, and the more the better.
The reality of course is little less glorious. Vitamin D is helpful in many health conditions, and there’s no doubt that most people could use more. But what about acne? Is there any good reason to believe vitamin D can help acne patients?
There is. As you know, hormonal acne is connected to insulin resistance. And anything that reduces insulin resistance can also help with acne. Though studies are still mixed there’s good reason to believe vitamin D may mitigate insulin resistance.
The sunshine vitamin may also have a more direct benefit for the skin. Test tube studies suggest it regulates sebum production and skin cell growth, and so help to keep your skin pores open and squeaky clean.
Let’s look at these in a bit more detail.
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One 3-year study looked at the effect of combined vitamin D and calcium supplementation on blood sugar metabolism in older people. In this study 314 over 65 years old adults took a daily supplement with 700IU or vitamin D and 500mg of calcium citrate, and the researchers followed them for 3 years. When looked as a whole group the supplement had no effect. But the group that had started the study as insulin resistant showed benefit. Their insulin resistance and blood sugar levels remained stable, whereas insulin resistant placebo group got worse as time passed. So it looks like the supplement had a protective effect.
The odd thing about this study is that even the insulin resistant group had blood vitamin D levels of over 70 nmol/l, which is far from deficient. Given such starting levels it’s hard to know what to make of this study.
Another study looked at insulin resistant, vitamin D deficient (blood levels below 50 nmol/l), adult women. The women received either 4000 IU of vitamin D or placebo for 6 months. The supplement increased blood vitamin D levels significantly (median levels went up from 21 to 75 nmol/l). Fasting insulin levels dropped by 20 to 30% in the supplement group (depending on blood vitamin D levels). When compared to placebo group there was a significant improvement in insulin resistance and inflammation levels.
This study also noted that insulin resistance was improved the most when vitamin D levels reached 80nmol/l and that it took 6 months for insulin resistance to really improve.
There’s also a handful small studies with polycystic ovary syndrome (PCOS) patients. PCOS has very similar causes than acne (insulin resistance, hormonal imbalance and inflammation) and PCOS patients often also suffer from acne.
In many of the PCOS studies the starting levels of vitamin D are very low, in the range of 20 to 30 nmol/l. After supplementation vitamin D levels and insulin resistance improves.
Not all studies are positive
So far I’ve only talked about the positive studies. But that gives you a biased picture, as there are also a good number of negative studies. Some of these negative studies were done on people who were not insulin resistant, and the aim was to find out if vitamin D improves blood sugar levels. Some studies used larger, weekly doses of vitamin D as opposed to daily doses. Daily doses have been shown to be more effective at improving blood vitamin D levels.
Conclusion: Vitamin D probably helpful in insulin resistance
So what to make of this? Can vitamin D improve insulin resistance? Because of the conflicting results it’s hard to draw solid conclusions. Based on the studies I’ve seen I’m cautiously optimistic. I would say that:
It’s not possible to say more than that from the data we have. And even these conclusions are somewhat optimistic. In terms of scientific evidence what we have is still a little shaky. But given significant health benefits and little to no downside, I’ve decided to err to the side of optimism.
The skin not only produces vitamin D, but most skin cells also have vitamin D receptors. As acne patients we are especially interested in sebocytes (the cells that produce sebum). Test tube studies have shown that vitamin D reduces the growth of sebocytes. Fewer sebocytes means less sebum in the skin. But let’s keep in mind that these are test tube studies, and there’s no way to say if vitamin D supplementation or cream reduces sebum production in living humans.
There’s also evidence that vitamin D reduces skin cell growth and helps in differentiation at cell death. This is helpful because in acne patients skin cells tend to grow too fast and stick together after death, leading to clogged pores. Psoriasis is similar in this regard, and synthetic vitamin D cream has been shown to help psoriasis patients.
Let’s call all this as interesting but far from proven. But if you happen to come across with a vitamin D cream it’s probably worth a shot to try it.
So far we’ve looked at medical research, but what about actual users? What do they say about vitamin D for acne? The reviews at acne.org are surprisingly positive. Vitamin D gets an overall rating of 4 out of 5, which is very good. Many users report it helped with persistent acne that otherwise refused to budge.
Positive as they are, I would take customer reviews (like all anecdotes) with a grain of salt. The problem is that acne is cyclical. There are times when it gets better without you doing anything about it. When that happens at the same time you start taking vitamin D, it’s easy to conclude the improvement is because of vitamin D. As humans we often jump to such erroneous conclusions.
Time presents another problem. Most people make their positive testimonial too quickly, usually during the first one or two weeks of getting positive results. But they don’t correct it when acne reverts back to ‘normal’ 4 weeks later. So we have no way of knowing the real, long-term effects of vitamin D from these testimonials.
Finally, the ‘sample population’ in these testimonials is biased. The people who get positive results, even miraculous, tend to get excited and shout their discovery from the mountaintops. Whereas you rarely hear from people who got little to no results, most of them just don’t have the motivation to go online and share their experience. So we see the positive results but miss the negatives.
That said, the reviews are another indication that vitamin D is probably helpful for some acne patients.
There’s no shortage of screaming headlines touting the benefits of vitamin D in natural health websites. NaturalNews.com, for example, has repeatedly told that vitamin D slashes cancer mortality by 50%.
The problem with these claims is they are based on observational studies. Example, in the case of cancer they measure vitamin D levels from cancer patients with various forms of cancer. Then they try to see if people with more serious forms of cancer have lower levels of vitamin D.
These studies are good for examining possible links between nutrition and health problems. But based on these studies we can’t conclude that vitamin D slashes cancer risk. Correlation doesn’t equal causation. And we can’t say whether low vitamin D levels are the cause or result of cancer, or whether it’s just a coincidence.
With that in mind, here are common associations from observational studies.
One more time. These are observational studies, and we can’t say for sure vitamin D does all this. There really aren’t that many clinical trials to confirm or dispute these claims. But given consistent results from observational studies, I think it’s safe to say higher vitamin D levels do have some health benefits. Just what and how much we can’t say for sure.
The next obvious question is how much vitamin D you need. 2006 review published in the Americal Journal of Clinical Nutrition concluded this:
For all endpoints, the most advantageous serum concentrations of 25(OH)D begin at 75 nmol/L (30 ng/mL), and the best are between 90 and 100 nmol/L (36–40 ng/mL).
Other reviews have come to the similar conclusions.
There’s still quite a bit controversy about vitamin D and how much we need. The National Institute of Health is a bit more conservative. They state that 50nmol/l is sufficient for 97.5% of the population.
There doesn’t seem to be any risk going over the NIH recommendations. Some evidence shows adverse effects at levels of 150nmol/l. But even that’s questionable since outdoor workers have such levels from sun exposure alone, for example measures from lifeguards show 163nmol/l.
People with levels below 30nmol/l are considered vitamin D deficient.
Daily intake to reach optimal levels
The above 2006 review states that daily intake of 700 – 1000 IU per day takes 50% of younger and older adults into blood levels of 90 – 100nml/l. How much vitamin D supplementation increases blood levels depends on starting levels, how well it’s absorbed, sun exposure and other factors. And daily intake of 2000 IU takes 85 – 90% of people above 75nmol/l.
The current RDA of 600 IU per day takes most people to levels between 50 – 60 nmol/l, level which many consider to be insufficient.
One study estimated that it takes 1000 IU per day during winter to maintain levels of 70nmol/l the participants had at the end of the summer. Those with starting levels of 20 – 40 nmol/l required 2000 IU per day to reach the same levels.
So based on all this, 700 – 2000 IU seems to be the optimal daily intake of vitamin D.
Contrary to most other vitamins and nutrients, aside from a few exceptions diet is not a very good source of vitamin D.
The food sources high in vitamin D include:
On average you may get 400 – 500 IU from diet. And that’s if you pay special attention to eating vitamin D rich foods.
Compare that to what sunlight can do. Sunlight exposure in bathing suit long enough to turn the skin slightly pink raises vitamin D levels the same amount as taking 10’000 – 20’000 IU supplement.
Most health authorities say that exposing hand, feet and face to midday sun for 15 minutes a few times a week is enough to meet the vitamin D requirements for most people. But this probably refers to somewhat low recommendations by the National Institute of Health.
Vitamin D free months
Whether your skin can produce vitamin D from sunlight depends on the angle of the sun. During winter months in most of the Western world the angle is such that the skin cannot produce any vitamin D.
At latitudes of 37oN and above these vitamin D free winter months start about mid-October and last until mid-March. Obviously the higher North you go the longer this vitamin D free period is. At Southern hemisphere the situation is mirrored and you go with 37oS and south from that.
For reference San Francisco sits exactly at 37oN latitude. Wikipedia has a helpful page that lists cities by latitude.
Other factors that affect how much vitamin D the skin produces
Not every skin produces the same amount of vitamin D from the same sun exposure. Studies have shown that the skin of 80 year old person produces only half the vitamin D that of 18 year old person’s skin.
Obesity causes similar problems. One study compared how UV exposure affects blood levels of vitamin D in obese and lean people. Compared to lean people the obese subjects had 57% lower blood vitamin D levels after the same UV exposure. The study authors believe this is because of lower bioavailability in obese subjects.
These recommendations should take you to the safe side with regards to vitamin D.
Based on current medical evidence vitamin D might be helpful for some acne patients. It may be especially helpful for those with insulin resistance or other blood sugar problems, both of which contribute to hormonal acne. Though results from clinical trials are somewhat conflicting, there’s a good reason to believe the sunshine vitamin mitigates insulin resistance and blood sugar problems.
Women with PCOS are also good candidates. Several studies have shown promising results with PCOS, with improvements in insulin resistance, hormone levels and menstrual frequency.
As to acne patients without blood sugar problems, vitamin D may not do much for your acne. At least I didn’t find anything in the medical research that would say so. That said vitamin D has other health benefits, such as ‘boosting’ the immune system and protection against heart disease and cancer.
Aim to get 700 – 2000 IU of vitamin D per day, depending on your current vitamin D status, skin color, where you live, time of the year and your diet. That should be enough to get your blood levels to 90 – 100 nmol/l, a level that’s been shown to be optimal for many health conditions.
You can get some vitamin D from diet, especially if you regularly eat fatty fish and sea food. But that’s unlikely to be enough. During summer months you can get enough by exposing your face, arms and legs to sunshine for 15 minutes a day. During winter and anytime you aren’t spending time outdoors, consider taking a vitamin D supplement.
Acne doesn’t have to be confusing or complicated. I can promise that in 10 minutes (the time it takes you to read the next 2 articles) acne finally starts making sense - and you know how to boot it out of your life.
Seppo Puusa, a.k.a. AcneEinstein shares rational advice about natural and alternative acne treatments. Read more about me and my acne struggles at the about me page.